1. Field of the Invention
The invention relates to a method of generating clean electrical power from atmospheric convective cells anchored and controlled by a high-power microwave beam within the absorption band of oxygen.
2. Discussion of Related Art
Global warming due to human activities releasing ever larger quantities of carbon dioxide—a major greenhouse gas—into the atmosphere has become a main concern for the future development of civilization. One important step in solving this immense problem is decarbonization of electrical power grids—worldwide. Everything possible that can help should be done, but the highly predictable environmental catastrophe will not be avoided unless thousands—tens of thousands—of gigawatt-level, zero-emission electrical power stations are put into use by mid century.
Currently, there are about 4 terawatts (TW) of installed capacity to produce electrical power worldwide—almost all of it relies on non-renewable sources, including nuclear. In the USA, the installed capacity is about 1 TW. On average, 50% of capacity is actually used due to unavoidable fluctuation in demand. In 2005, 49.7% of the production was from coal; 19.3% from nuclear; 18.7% from natural gas; 6.5% from hydro; 3% from oil; 1.6% from biomass; the balance of 1.2% from geothermal, solar and wind. Thus only 9.3%—most of it from hydro—was renewable and over 71.4% resulted in carbon dioxide release.
Notwithstanding the rapid increase of wind and solar electricity production, there has been no overall increase in relative use of renewables during the last few years—in absolute terms, use of coal and gas has grown even faster. Worldwide total energy need is about 15 TW and it may expand to 50 or even 100 TW by the end of the century. As oil supplies peak and then decline, electrical energy will be expected to replace most of it. Of the current technologies not resulting in carbon dioxide release, only nuclear power could be scaled up to meet this demand quickly enough, but for many reasons this will not happen. Furthermore, supplies of uranium are also exhaustible.
Even if nuclear fusion makes a breakthrough, it will not eliminate some of the major concerns with nuclear power generation. Sequestration of carbon dioxide, while technologically feasible, fails to satisfy the fundamental need to turn to renewable sources.
The present invention provides a renewable source for electricity generation utilizing a solar chimney created by a microwave beam to form an artificial tornado.
In the prior art relating to the vortex as an “artificial tornado” (Michaud L M U.S. Pat. No. 7,086,823; Michaud L M, Vortex process for capturing mechanical energy during upward heat-convection in the atmosphere, Applied Energy, 62, (1999): 241-251) it has been assumed that once established the vortex would remain stable based only on what one could consider boundary conditions at ground level. While a tornado provides a useful illustration and has motivated this inventor, as well as others referenced herein, use of the vortex as a stable conduit to higher atmosphere requires mechanisms beyond any offered by prior art proposals.
A natural tornado is a fleeting phenomenon arising from a confluence of factors in a much larger storm system. Energy must be expanded to maintain the vortex and it must be used deliberately to replace the conditions, which in the natural tornado are produced by the storm system surrounding the tornado vortex itself. However, the tornado, and in particular the dreaded suction vortex, do teach the physical possibility of a “dynamic chimney”.
Computer simulations of the tornado, which can replicate the naturally occurring wind patterns, use a “forcing function” to model the vertical updraft in the center of the tornado (Nolan D S, Almgren A S, Bell J B, Studies of the relationship between environmental forcing and the structure and dynamics of tornado-like vortices, Lawrence Berkeley National Laboratory Report LBNL-47554, September 2000), which, in nature, is the result of a thermal anomaly, i.e. the presence of air warmer at an altitude of several kilometers above the ground than at ground level. There would be no tornado without the forcing function—and if the forcing function were placed at ground level, the vortex would not reach to higher altitudes. In fact, the vortex of a natural tornado is established at higher altitudes and it only touches the ground as it stretches downwards along its axis of rotation.
The conventional solar chimney concept has been well tested and there are plans now to build large power plants at 100's MW level (Schlaich J, Bergermann R, Schiel W, Weinrebe G, Design of Commercial Solar Updraft Tower Systems—Utilization of Solar Induced Convective Flows for Power Generation, J. of Solar Energy Engineering, 127 (1), (2005): 117-124). The power of a solar chimney plant is approximately proportional to the volume defined by the height of the chimney and the greenhouse roof at the ground. Recent plans for a large plant in Australia call for a 1000 m tall chimney and a 7 km-diameter glass roof for a 200 MW plant. A “dynamic chimney,” created by the microwave beam according to this invention, could reach to 5000 m or higher and thus increase the power of such a plant five-fold to the gigawatt range, with all of the plant structure remaining near the ground level.
U.S. Pat. No. 3,936,652, by Steven K. Levine, discloses a power system based on updraft generated by a cooling tower of an existing power plant, e.g. a nuclear power plant.
U.S. Pat. No. 4,397,793, by Gerald I. Stillman and Rudolf A. Wiley, discloses a method of increasing the efficiency of a cooling tower or a stack, by introducing a vortex via vertical slits in the wall of the tower or stack.
U.S. Pat. No. 4,499,034, by John E. McAllister, Jr., discloses a cooling tower supplemented by a vortex which increases the efficiency and thus allows for power extraction via windmills placed into the inlet passages.
U.S. Pat. No. 5,483,798, by Melvin L. Prueitt, discloses convection towers wherein the airflow is driven by cooling the air via water sprays.
U.S. Pat. No. 6,772,593, by Michael A. Dunn, discloses a vortex driven power station, whereby the air is warmed up under solar collectors—a concept similar to the solar chimney, already referenced above.